Quarterly Journal of Microscopical Science, Vol s2-78, 71-90, Copyright © 1935 by Company of Biologists

Memoirs: The Early Embryonic Development of Rhodnius Prolixus (Hemiptera, Heteroptera)

¹ Department of Zoology, University College, London

1. Eggs of Rhodnius prolixus were incubated at constant temperature and humidity (21° C. and 90 per cent, relative humidity). Eighty-five per cent, was the lowest record of the controls hatched successfully under these conditions.

2. The processes of maturation and fertilization were not studied.

3. Cleavage begins 12-13 hours after incubation. At 25 hours there are 32 nuclei. Yolk-cells are derived from cleavage nuclei, and they multiply by mitosis up to 50 hours. Blastoderm formation is complete after 55-60 hours of incubation.

4. The ventral embryonic rudiment is similar to that of many other insects. As soon as it is formed, germ-cells are budded off at the posterior pole of the egg.

5. The first stage in blastokinesis is fully described.

6. The formation of the mesoderm is by invagination and overgrowth.

7. The endoderm arises from two proliferating areas situated anteriorly and posteriorly.

8. Numerous cells are given off into the yolk during the early development of the embryo. There they disintegrate.